The American Pledge of Allegiance currently reads: "I pledge allegiance to the Flag of the United States of America, and to the Republic for which it stands, one Nation under God, indivisible, with liberty and justice for all." Although the "one Nation under God" has been recited in the pledge for decades, it did not exist in the original version--instead, it was added in 1954 by president Dwight Eisenhower. In part, it was intended to be something that set the United States apart from other countries.
Since the addition of "under God," some have claimed that it violates the U.S. Constitution, particularly the Establishment Clause, which statest that "Congress shall make no law respecting an establishment of religion." Opponents of the phrasing of the Pledge believe that the words "under God" indicate a promotion of the Christianity. Although there have been no recent movements to change the Pledge, it continues to be a controversial topic.
I personally think it does seem like it could violate the Establishment Clause, even though I am a Christian and I do stand for and recite the Pledge. Even though it is meaningful to me, I can imagine that it could be uncomfortable for somone with different religious views. The only arguments I can see in favor of the "under God" not violating the Establishment clause is 1) recitation of the Pledge is not required by the government or 2) "under God" could be referring to monotheistic religions other than Christianity. What do you think?